1. Field of the Invention
The present invention relates to the field of compressed air and gas systems, and more particularly to filtering and drying equipment for filtering and removing moisture from compressed air and gas delivered to air/gas-driven tools.
2. Description of Prior Art
Typical compressed air or gas produced by a compressor apparatus is saturated with 50% to 100% relative humidity, and also contains contaminants such as dirt, dust, oil, line debris and other matter. Filters and traps remove liquid water and other contaminants but do nothing to eliminate the 50% to 100% moisture vapor still remaining in the compressed air or gas. The removal of this moisture vapor requires that an air/gas dryer system be used, such as a refrigerated dryer or an adsorbent type of dryer. Such systems are generally very effective, the latter being typically capable of drying compressed air or gas to below-zero dew point levels. However, even basic dryer systems are relatively expensive, can be difficult to install due to their large and bulky nature, and require regular maintenance to ensure proper operation. Individuals and other entities with limited financial resources, or who do not use compressed air/gas on a regular basis, may elect not to install drying equipment in their compressed air/gas systems, and instead use compressed air or gas that has not been treated to remove moisture vapor. Even if a dryer system is installed, there is no guarantee that the compressed air or gas will have the desired dryness by the time it arrives through an air/gas feed system to a downstream point of use. Compressed air lines, various fitting and regulation devices, or improper operation of the dryer system all represent sources of residual moisture vapor in the air/gas feed system. This means that compressed air or gas that has been moisture-treated may not have the desired dryness characteristics by the time it goes into use as an application. This can cause problems in applications such as paint booth operations where compressed air or gas is used as a propellant to atomize and expel paint from a paint gun. If moisture-laden ambient air is delivered through the air/gas line, it will feed through the paint gun, and may cause unwanted fouling that results in a bad and unacceptable paint job.
It is to solving the foregoing problems that the present invention is directed. What is particularly needed is an improved air/gas dryer that is easy to install and use, simple and inexpensive, and requires no maintenance. The dryer should be suitable for use as the primary or sole air/gas moisture vapor treatment apparatus in a compressed air/gas system, but should also be usable with existing dryer systems. Adding a filtering function to such a dryer would be further desirable.